Manufacture of lead arsenate.



ELLE RSLIE E. LUTHER AND WILLl'All I H. VOLCK, OF"W SONVI LLE, CALIFORNIA.

MANUFALTUBE OF LEAD .ARSIENALTE.

Specification of Letters Application filed August 15, 3907.

Patent. Patented Aug. 3, 1909.

Serial in. 888,711.

To all 10/ 207)) it may concern:

Be it known that we, ELLERSLIE E. LUTHER and VJILLI M H. VoLcK, both citi Zens ol" the United States, residing at at sonyillc, in the county of Santa Cruz and State of California, have invented new and useful Improvements in the Manufacture of Lead Arsenates, or" Which the following is a 1 specification.

ur invention relates to improvements in r the manufacture of lead arsenates.

consists in the process and method which will be more l'ully explained in the following specification.

ur process consists in the formation of lead arscnates, by roasting the combined parts in the presence of oxygen.

The ordinary process for the manufacture of lead arsenates is a precipitation process, Where soluble salt and arsena-te are brought togctl'ier in their proper combining Weights, and this process may be properly divided into three stages first, the manu facture of lead acetate; secondly, the manufacture of sodium arsenate; and finally, the reaction between the foregoing parts.

Uur process may be carried. outin slightly different Ways. Thus, We may form lead .rsenite and oxidize it to lead arsenatc by roasting in the presence of oxygen. The lead arsenite is produced by heating White arsenic (As O With lead or oxid of lead (PbO), and the further roasting will result in the load arscnate. The arsenate formed by amixture of lead arsenite and lead ars'enate, by heating: red lead (Pb OQ with White arsenic, and its subsequent oxidation by roasting in the presence of oxygen. Or the lead arscnate may be formed directly roasting White arsenic ("As OQ oXid (1 b0,) or lead nitrate With one of the oxidizing agent.

(Pb N09,,

or lower oxids of lead with an may also be' with lead pei Combining Weights of White arsenic and the lead compound then react upon each other, in the presence of oxygen, either derived from the air by the action of the heat applied. arious temperatures may cient, under different conditions, but We have found that for the production of arse nate of lead, which is the particular metallic arsenate h re described, a temperature of between 300 and 400 degrees centigrade is very effective. By this process-we are enabled to produce the arsenate at a single operation, and at a considerably reduced cost. Having thus described our invention,.wl1at I l i two claim and. desire to secure by Letters Patent 185 1. The process of producing lead arse- I nates, the same consisting in roasting-comining Weights 01 White arsenic and lead compound in the presence of oxygen.

White arscnic'in contact With a compound, and continuing the J heating and roasting the combined material I in the presence of oxy en. l he process of producing lead arse-notes, the same'consisting in heating a lead compound and White arsenic together, and continuingthe heating and roasting the combined materials in the presence of an oxidizing agent.

In testimony whereof" We have hereunto set our hands in presence of two subscribing: Witnesses.

ELLEasLIn 13. LUTHER. WILLIAM H. VOLCK. VVitnesses:

W. A. BUCKHART, THos. W. FIRBY.

or otherwise supplied, and

be found efii- 2. The process of producing lead arsenates" said method'consistlng 

